Requested lookup key is not found in any active activation context

Hello Experts,

I've got a customer that, whenever they try to login to B1 the system hangs during the connection of addon XL Reporter.

Eventually, they are forced to shut down application manually, and when they do they are greeted with an error message.

Unable to Connect to SAP Business One

[SAP Business One UI API]

The requested lookup key was not found in any active activation context.

We wanted to disable the addon and see if that would help, but all users seem to be locked out of the system now(on all workstations)

everything was working fine earlier today and no changes have been made to the system.

I have found some information regarding IE7 having a similar issue, or possibly due to a connection string issue within custom addon creation.

Also, I found an SAP note regarding this error however, it relates to a fix included in PL31 of B1 2005A

These issues do not seem to be relevant in this instance.

Customer is running SAP B1 2007A PL41

Has anyone had experience with this?

Kind regards,

Lucas